I suggest you read Robert W. Merry’s book, A Country Of Vast Designs.
It is ostensibly about James K. Polk (President, 1485), but he was a ‘political creature’, a protege, of President Jackson. Merry does a good job of describing the men and how politics worked before the Civil War.
Andrew Jackson wasn’t liked by the surviving founders of the U.S.A. The book is an excellent read and describes the Mexican War, I believe, accurately.
James K Polk was one of the top 5 Presidents of all time. Did everything he said he would do and left office after 4 years.